An aircraft may be frozen due to a low temperature when the aircraft is flying at high altitudes. In the icing conditions, if the aerodynamic sensitive part of the wing, for example the leading edge, is frozen, the aerodynamic shape of the wings will be influenced. The wings might stall due to freezing and the flight safety will be threatened. Therefore, in order to prevent the sensitive parts, such as the leading edges of the wings and the like, from freezing, the pneumatics system of the aircraft provides hot air to the slats of the wings to remove the ice and prevent freezing.
The wing anti-icing valves control the opening and closing of the hot air piping and ensure that the pressure of downstream of the piping is within a certain operating range. The reliability of the anti-icing valves greatly affects the flight safety. Once there is failure in the anti-icing valve, the aircraft operation will be influenced. Even if the artificial operation may be applied, the flight is still easily to be delayed. Therefore, monitoring the performance of the anti-icing valves may help improving the reliability of the aircraft and reduce the running cost.